Labeling machines are known which, according to a widespread type, comprise a rotating carousel that supports, at its peripheral region, a plurality of pans, each whereof is designed to receive and support a bottle that is conveyed by an input star conveyor when, as a consequence of the rotary motion of the carousel, it is in a specific position at such star conveyor.
Labeling machines are known that in order to operate on specific types of labels, such as for example labels imprinted consecutively, one after the other, on a film that unwinds from a reel, have means adapted to rotate the pans about their own axis while they travel, entrained by the rotating carousel, along a portion comprised between a rotation start position and a rotation end position.
Commonly, the means adapted to rotate the pans about their own axis comprise a toothed belt, which is designed to make contact with pulleys that are rigidly coupled to said pans, and in conventional machines such belt is subjected to intense stresses, which cause a limited life of the belt.